Feeding includes food acquisition, ingestion, digestion, and
absorption. This activity relieves hunger and provides multisensory
stimulation, resulting in a pleasant, rewarding experience for both
the child and the caretaker. Successful feeding experiences create
positive reciprocal interactions that reinforce the bonding relationship
between child and caretaker. Feeding disorders prevent the infant
from ingesting adequate nutrients for continued health, growth,
Feeding and swallowing are complex processes that can be divided
functionally into 4 phases, as shown in Figures
31-1 and 31-2. The preoral phase is
initiated when the child senses and communicates hunger. The oral phase is
a food-processing step wherein the ingested material is formed into
a bolus that can safely pass through the pharynx; the remainder
of the swallowing process is involuntary and reflexive. The pharyngeal
phase is quite rapid. It is initiated by bolus contact with
the tonsillar pillars and pharyngeal wall with subsequent elevation
of the larynx, vocal cord closure, and relaxation of the upper esophageal
sphincter. A peristaltic wave of contraction of the pharynx propels
the bolus into the esophagus.
Model of the normal phases of feeding in infants and children. Complex interactions between phases often obscure diagnosis of the primary cause of a feeding disorder.
A: The infant oropharynx. The
larynx is elevated with the epiglottis touching the soft palate,
creating a functional separation between the air passages (white
arrow) and the food passages (black/gray
arrow) in the pharynx. Food courses around the epiglottis,
into the pharyngeal recess, and then to the esophagus. B: The
toddler (2–3 years old) oropharynx. C: The
adult oropharynx: (1) oral preparatory phase, (2) oral
phase, (3) pharyngeal phase, (4) esophageal
phase. Note that the infant oral cavity is much smaller
than the child or adult oral cavity, providing little space for
manipulation of the food bolus. The larynx is elevated so that the
epiglottis almost touches the soft palate, and the larynx is at
the level of the first to third cervical vertebrae. The tongue is
entirely within the oral cavity, with no oral region of the pharynx.
In the toddler, the larynx descends to the fifth cervical vertebra,
and by adulthood it descends to the sixth to seventh cervical vertebra.
During passage of the bolus through the pharynx, excellent coordination
between breathing and swallowing is essential to prevent aspiration.
In the esophageal phase, the bolus is transported
into the stomach. Finally, the bolus is broken down and absorbed
during the digestive phase. Developmental and maturational changes
in the phases of swallowing occurring from infancy to childhood
can have a significant impact on a child’s ability to feed successfully.